He was highly visible in the US media, going on popular television talk shows, including Montel Williams and Sally Jessy Raphael, and agreeing to tell his story in newspapers and magazines in the hopes of finding a clue to Savanna's whereabouts.

Photos of Savanna and her mother, digitally aged as the years progressed to show what they would look like, were circulated on law enforcement and missing persons websites for two decades.

Mr Todd also launched a civil court case in South Carolina against his ex-wife.

The judge was so taken with the suffering the father had endured he awarded Todd $US50 million in damages.

The money was not the goal.

What Todd and Sturgis wanted was to subpoena and take depositions from people they believed knew where Savanna was, or had helped Barnett flee.

Sturgis described the $US50 million as "totally uncollectable" and the "bits and pieces" of information they collected during the court proceedings "all pointed in different directions".

Barnett is accused of fleeing with Savanna to Europe, eventually marrying a man in South Africa, then moving to New Zealand, before settling in Australia in 2007.

Barnett, 53, is in custody in Queensland and has been indicted in the US on parental kidnapping and making a false statement on passport application charges.

The US plans to extradite her and if convicted, she faces more than 20 years' jail.

Savanna, now 20 and attending James Cook University, is standing by her mother.

Sturgis would not say if Todd was in Australia or planned on flying there to meet his daughter, but he said Todd's focus was on Savanna, not what his ex-wife had done.

"He is a good, intelligent caring person," Sturgis said.

"If there's any way for Savanna to build a relationship with a father she has never known, he's there to do it.